tunnel sensors

dear,

i was wondering concerning tunnel sensors, my preference is for IP66 for tunnel sensors such as visibility, CO, NOx etc....
however, most of the sensors are IP65, you can find IP 66 sensors from some vensors such as SVS1 sentry (visibility sensor) from envirotech.
My preference is for IP 66 is that the tunnel might be cleaned and this might damage the sensor, do you think IP 65 can handle cleaning?
appreciate your advice

thanks!

charbel

go for Ex units explosion proof, it might be needed as some units should work even when there is a fire in the tunnel.

shooter said:

go for Ex units explosion proof, it might be needed as some units should work even when there is a fire in the tunnel.

Click to expand...

Ex property and fire resistance are not the same. Ex equipment are designed in that way if it malfunctions it won't cause spark or heat or in any other way CAUSE a fire or explosion so it's anti-explosive
Fire resistance means only that it is resistant to open flame in certain degree. (e.g some cables that are resistant up to 90 min.)
Fire resistant materials are used in enviroment when power is critical even in case of fire (e.g. springler systems, server cabinets, emergency power) while Ex unit are obligatory in explosive enviroments.

Now considering that, i'd think since there is no risk of explosion in tunnel there's no need for Ex equipment i.e. extra cost (plenty of paperwork specific maintenance, certificates, etc....)

As for IP protection 5 in 65 is pretty high protectionfrom all directions, unless someone decides to use really strong industrial mini-washes during cleaning.

http://www.2mcctv.com/blog/wp-content/uploads/2011/10/ip-ratings-chart1.jpg

What type of cleaning are you referring to
there IP65 and 66 is very close

dear iant,

i was wondering if strong jet of water would be used and to be on the safe side IP 66 would be used.

It would be better if you can avoid that
What about a Perspex cover in front of the sensor. I understand the sending distances.

cover could be just on critical places as it would only need to protect from direct bursts from jet, as 5 protect from splashes...

http://www.lpc-uk.com/omron/ind.htm
these are IP67 and IP68
other manufacturers have this equipment.
but I still would not rely on them surviving a direct blast of water.
the plastic moulding usually breaks down and water gets in.
QUOTE "Doctor Who - Waters of Mars" water always wins